I posted this in responce to a discussion here, and I just had to preserve it here.
Using some rough values I found on the Intertoobes , one slice of bacon weighs 29 grams and has 12 grams of fat. Those 12 grams of fat will produce 444 kJ of energy. The specific heat of bacon is 1.51 kJ/( kg deg C ), so those 12 grams of fat, if converted perfectly to heat, could raise 294 kg of bacon 1 degree C. Going from room temperature (20 deg C) to the safe temperature for consuming pork products (70 deg C) is a change of 50 deg C, so that energy could move about 5 kilograms of bacon from room temperature to a safe eating temperature.
I'm slightly not sure about this answer, but I suspect that the problem is that in the messy real world no burning process would turn the energy in the fat in the bacon perfectly into heat that could cook bacon. So there's likely some sort of fudge factor there, and also this assumes that my brain can do calculations like this on a Friday evening --- corrections are welcome. And, of course, depending on your desired outcome you may only care about getting the fat liquid enough so that it could flow and serve as a fuel, or you may care about getting the bacon to the desired crispyness level (which may require a higher temperature).
Of course, what you are doing here is not making a perpetual motion machine, since you are constantly putting in energy in the form of supplemental bacon (that is, if you stop putting bacon in, you eventually will stop getting energy out). What you really have is a rather inefficient (but delicious) long-tail solar power generator: the sun provides the energy to grow crops which provides the energy to make pig which provides the energy to cook pig. There's probably some renewable energy grant you could get for this.
: Goddess bless America that I can think "I wonder what the specific heat of bacon is" and *find* an answer online.